Structure-Activity Relationships in Coumermycins

Abstract

This chapter focuses on the structure–activity relationships in coumermycins. The naturally occurring coumermycins are produced in fermentation broths of several species of Streptomyces. Degradative studies at Bristol–Banyu Research Institute established the structures of coumermycins A1 and A2. Several bioactive components, including coumermycin A1, were elaborated by Streptomyces rishiriensis, which was isolated from a soil sample collected in Rishiri Island, Hokkaido, Japan. Another Streptornyces isolate, originally designated as species X-7763 by the Hoffmann–LaRoche group, was obtained from a soil sample collected in Gaspe, Canada. It was also found to produce multiple antibiotics, each containing a coumarin-like moiety. Chromatographic and degradative studies revealed the fact that the antibacterial activity of the culture filtrates was attributable to a number of closely related substances. Among the naturally produced coumermycins, the degree of methylation of the terminal pyrrole moities and the presence or absence of this heterocyclic function correlates positively with intrinsic biopotency and vary probably with breadth of antimicrobial spectrum. © 1972, Academic Press Inc.